The invention relates to an attractant for ants, in particular for the Pharaoh's ant (Monomorium Pharaonis L), as well as to novel substances applied in this attractant and active as attractant and trail-following compound and to methods for the preparation of these novel substances.
The use of agents to attract insects in a condition in which they can be killed or made innoxious, is known in the art. So, for instance, insects can be lured to a certain place with the aid of the attractive agent and there be brought into contact with an insecticide, an insect hormone or an insect pathogen. In this way it is not necessary to spray a pesticide excessively and indiscriminately over large areas, but the combination of pesticide and attractant can be brought as a mixture or by the side of each other on or near the places that have to be protected against the noxious influence of the insects. The attractant can, for instance, also be used in a way known in the art in combination with a trap, enabling one to kill the insects in the trap or stick them onto an adhesive provided on one of the walls of the trap.
An other important application of attractants is signalling the presence, the distribution and the population of the insect. As a result, the presence of the insects can be discovered in time, so that the necessary measures for combating the pest can be taken and it is not necessary to use an insecticide outside the periods of presence of the insects. Moreover, with an attractant a much better picture can be obtained of the extent and the intensity of an insect pest, enabling a more accurate determination and focus of the measures to be taken to combat it.
Ants, of the type of the Pharaoh's ant, in many places form a danger for public health and mostly are extremely difficult to combat. In particular, in buildings with central heating, in bakeries and laundries, but also in private houses they are a great problem. The Pharaoh's ant is an important factor of pathogenous micro-organisms for man in many hospitals (see, for instance, Susan H. Beatson, The Lancet, 19th Feb. 1972, page 425). In such places, where the use of toxic substances ought to be avoided as much as possible, attractants are of great importance as a combating means.
In applicant's pending U.S. patent application Ser. No. 459,358, now abandoned in favor of continuation application Ser. No. 646,611 a new powerful attractive agent for ants, such as the Pharaoh's ant (MONOMORIUM PHARAONIS L) has been described, viz. the 5-methyl-3-n-butyl-octahydroindolizine.